Author Topic: "Check Trans" Light  (Read 727 times)

Robin Goffrier

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"Check Trans" Light
« on: July 14, 2020, 05:39:56 AM »
So I'm cruising up Highway 97 from Bend, destination Prosser, WA in my 06/525 Cat PT with the Allison 4000.  Couple idiot light ABS, Step out and ATC start erratically flashing on/off.  I pull off the road at Shaniko.  Step's not out and I figure a ground wire must be bouncing around somewhere behind the dash.  Then I notice as well, a red Check Trans Warning.  I got the manual and looked for the accompanying symptoms, like flashing digits on readout, shifter locked up, elevated temp and low oil. Nothing.  So I did what any techno challenged guy would do, I shut it down and then restarted.  No more warning light so off we go for the 100 mile remainder of the trip, no issues.  Wineries mostly shut down cause of the dread bug so we decided to leave the next morning for Anacortes.  No warning lights of any kind, Trans oil read "OK" so off we go.  About 4 hours into the trip, on comes the Check Trans light again. Coach is running fine and shifting perfectly.  But then I notice it won't shift into 6th gear, 1,750 RPM and 70 MPH in 5th  but wont go into 6th.  Drove the last 40 miles in, let her cool down, shut her down and in a bit restarted.  Again warning gone.  There;s a FreightaLiner dealer in Mt Vernon Who I'll talk to tomorrow.  I'd like to get her back home to Bend where I know the coach docs.  Any thoughts?
Robin and Barbara Goffrier
2006 Patriot Thunder, Cat C13 (2019 - )
2008 42' Contessa Milan, Cat C9s (2017 - April 2019)
2001 40' Marquis Saphire, Cat C12 (2015- 4/2017)
Winnebago 34, ', Itasca, 32', Allegro Bus 35' (previous)
Jeep Wrangler Unlimited
Bend, OR

Eric Maclean

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Re: "Check Trans" Light
« Reply #1 on: July 14, 2020, 01:18:19 PM »
Robin
Your transmission has an intermittent fault code setting .you need to extract the code through the shift pad to determine what the problem is.
I had much the same problem a year ago the trans light would come on and the trans would stay in fifth gear or nutreal
The code that was set was for the C3 pressure switch.
The C3 pressure switch inside the trans tells the ECU when the C3 clutch has oil pressure applied the code was set because the C3 switch was telling the ECU that there was pressure at the C3 clutch when the ECU had not comanded that clutch to engage
The ECU s response is to set the code and default into a gear which uses the C3 clutch to avoid having the trans in two years at once and the damage that would result.
In my case when I pulled the trans pan down and diagnosed the problem I found the C3 switch was not bad but I had a short in the wiring harness inside the transmission where it had rubbed on the housing and the wire for the C3 switch which is a grounding switch was intermittently shorting to ground which was setting the code.
Simple fix but required removing the bottom section of the trans to access the problem.
The problem I had only happened when the trans was up to operating temperature and even then only intermittently.
Your problem may not be the same ,you need the code or codes to work from.

To retrieve the codes with key on not running push both the up arrow and down arrow on the shift pad at the same time twice to enter the diagnostic.
If you PM me your email address I will try to send you the Allison 4000 troubleshooting manual

Hope this helps Eric
« Last Edit: July 14, 2020, 03:02:25 PM by Eric Maclean »
1997 Patriot Yorktown
3126-B
2009 Chevy HHR
Roadmaster falcon tow bar
Demco Air Force one tow brake.
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Steve Huber Co-Admin

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Re: "Check Trans" Light
« Reply #2 on: July 14, 2020, 04:17:21 PM »
Robin,
I had a similar problem with the Allison 4000 in my 00 Marquis. Was running fine. Stopped at a stop sign and when I accelerated it would not come out of 3rd. Had coach towed to Interstate Power in Minneapolis. Tech ran diagnostics and  said problem appeared to be an internal clutch ($$$). But he suggested we drive it around the block so he could verify the shift issue before he tore the tranny down. It shifted perfectly! Problem was intermittent connection(s) in wiring harness at tranny. His unplugging to connect the tester and then re-plugging corrected the bad contact. Was on my way after they replaced the wiring harness / connectors.
Steve
Steve
2015-          07 Contessa Bayshore C9,  400 hp
2013-2015: 00 Marquis Tourmaline, C12, 425 hp
2005-2013: 01 Contessa Naples, 3126B, 330 hp
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Eric Maclean

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Re: "Check Trans" Light
« Reply #3 on: July 15, 2020, 01:40:55 AM »
Robin
In my past work I did a lot of busses and trucks with Allison's and as Steve was saying I have several times come across loose connections to either the transmission umbilical plug or right at the TCM.
With the number of other things effected by your fault it would be prudent to check the harness plugs in those areas

Your entry door step and or leveling Jack's are sometimes tied into the TCM on some coaches to invoke a shift inhibit when the step is out or the Jack's are down.

Steve has added the Allison troubleshooting manual to the coach assist to help you pull the codes so you can get closer to a diagnosed.

Hope this helps
Eric
1997 Patriot Yorktown
3126-B
2009 Chevy HHR
Roadmaster falcon tow bar
Demco Air Force one tow brake.

Robin Goffrier

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Re: "Check Trans" Light
« Reply #4 on: July 15, 2020, 02:38:22 PM »
Thanks guys. Coach scheduled in Allison shop Thursday morning for diagnostic.  Keep you posted.
Robin and Barbara Goffrier
2006 Patriot Thunder, Cat C13 (2019 - )
2008 42' Contessa Milan, Cat C9s (2017 - April 2019)
2001 40' Marquis Saphire, Cat C12 (2015- 4/2017)
Winnebago 34, ', Itasca, 32', Allegro Bus 35' (previous)
Jeep Wrangler Unlimited
Bend, OR

Robin Goffrier

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Re: "Check Trans" Light
« Reply #5 on: July 17, 2020, 02:54:08 PM »
Took coach to Freightliner in Mt Vernon. Code said " communication failure". Resets after shut down. Goes about 3-4 hours trouble free.Tech could not find TCM unit. Will push for home.
Robin and Barbara Goffrier
2006 Patriot Thunder, Cat C13 (2019 - )
2008 42' Contessa Milan, Cat C9s (2017 - April 2019)
2001 40' Marquis Saphire, Cat C12 (2015- 4/2017)
Winnebago 34, ', Itasca, 32', Allegro Bus 35' (previous)
Jeep Wrangler Unlimited
Bend, OR

Mike Shumack

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Re: "Check Trans" Light
« Reply #6 on: July 17, 2020, 03:52:36 PM »
On the 2005 Patriot Thunder, the TCM (Allison ECU) is located in the compartment below the driver's left side console. The Allison VIM is in the Front Run bay.

- Mike

'05 Beaver Patriot Thunder 525, Vicksburg, CAT C13, Allison 4000MH, HydraLift
Orlando, FL

Robin Goffrier

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Re: "Check Trans" Light
« Reply #7 on: July 20, 2020, 07:59:49 PM »
Thanks guys. Here's the latest.  The Allison guys at Freightliner suggested that I unplug the SilverLeaf for the next few hundred miles to see if that made any difference.  I did and drove the 400 plus miles home just watching my analog panel. Nary a glitch, other than the "Step Out" light when I hit a bump.  No "Trans" warnings and no ABS or ATC idiot lights.  So my next question is, has anybody ever heard of a similar issue with the SilverLeaf and data port?  I love the big digital readouts on my tablet but at this point am a we tad suspicious that something related is corrupting the transmission control  unit communication to the ECM.  Or maybe its only coincidence that nothing happened when the Silverleaf was unplugged.  I called SilverLeaf Electronics in Albany and was told someone would get right back to me.  Nothing for the last couple hours.
Robin and Barbara Goffrier
2006 Patriot Thunder, Cat C13 (2019 - )
2008 42' Contessa Milan, Cat C9s (2017 - April 2019)
2001 40' Marquis Saphire, Cat C12 (2015- 4/2017)
Winnebago 34, ', Itasca, 32', Allegro Bus 35' (previous)
Jeep Wrangler Unlimited
Bend, OR

Steve Huber Co-Admin

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Re: "Check Trans" Light
« Reply #8 on: July 20, 2020, 09:28:48 PM »
Robin,
Just a thought. You might try using some contact cleaner on the connectors and then try plugging the Silverleaf back in. It's possible that a making/breaking contact caused the Allison to act up.
Steve
Steve
2015-          07 Contessa Bayshore C9,  400 hp
2013-2015: 00 Marquis Tourmaline, C12, 425 hp
2005-2013: 01 Contessa Naples, 3126B, 330 hp

Mike Shumack

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Re: "Check Trans" Light
« Reply #9 on: July 20, 2020, 10:12:15 PM »
has anybody ever heard of a similar issue with the SilverLeaf and data port? 
« Last Edit: July 20, 2020, 11:11:08 PM by Mike Shumack »
- Mike

'05 Beaver Patriot Thunder 525, Vicksburg, CAT C13, Allison 4000MH, HydraLift
Orlando, FL

Roy Warren Co-Admin

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Re: "Check Trans" Light
« Reply #10 on: July 20, 2020, 11:17:34 PM »
Contact Silverleaf in Oregon and I am sure someone there can give you help.
Roy Warren
Roy Warren
2005 Patriot Thunder
Cat C-13

Steve Huber Co-Admin

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Re: "Check Trans" Light
« Reply #11 on: July 21, 2020, 12:53:12 AM »
Robin,
You didn't specify if you had cruise control engaged when problem occurs. Reason for asking is that there have been some reports  regarding the check engine light illuminating when CC is engaged but with no ECM codes generated. So I'm sitting here wondering if something similar could be impacting the Allison TCU. Just another thought but my money is on a faulty connection as the symptoms seem to fit it IMHO.
Steve
Steve
2015-          07 Contessa Bayshore C9,  400 hp
2013-2015: 00 Marquis Tourmaline, C12, 425 hp
2005-2013: 01 Contessa Naples, 3126B, 330 hp

Robin Goffrier

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Re: "Check Trans" Light
« Reply #12 on: July 21, 2020, 03:03:25 PM »
Silverleaf called. They said although rare, there have been issues in the past that sound like mine. Their suggestion was to reconnect system and see if it repeats. Mentioned that tranny might not shift into 6th gear. If situation reoccurs their box would need to be analyzed/repaired.  Next trip in about 3 weeks. We'll give it a shot.
Robin and Barbara Goffrier
2006 Patriot Thunder, Cat C13 (2019 - )
2008 42' Contessa Milan, Cat C9s (2017 - April 2019)
2001 40' Marquis Saphire, Cat C12 (2015- 4/2017)
Winnebago 34, ', Itasca, 32', Allegro Bus 35' (previous)
Jeep Wrangler Unlimited
Bend, OR

Robin Goffrier

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Re: "Check Trans" Light
« Reply #13 on: July 22, 2020, 07:55:31 PM »
Steve, CC was not engaged.
Robin and Barbara Goffrier
2006 Patriot Thunder, Cat C13 (2019 - )
2008 42' Contessa Milan, Cat C9s (2017 - April 2019)
2001 40' Marquis Saphire, Cat C12 (2015- 4/2017)
Winnebago 34, ', Itasca, 32', Allegro Bus 35' (previous)
Jeep Wrangler Unlimited
Bend, OR